The number of renewable terms for an operating lease.

No definition available.

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- Definition

The number of collaboration and licensing agreements.

+ References

No definition available.

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- Definition

Number of financial institutions.

+ References

No definition available.

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- Definition

Number of operating lease.

+ References

No definition available.

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- Definition

The number of revenue related contracts.

+ References

No definition available.

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- Definition

Amount of asset related to consideration paid in advance for research and development expenses that provide economic benefits within a future period of one year or the normal operating cycle, if longer.

+ References

No definition available.

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- Definition

Summary Of Significant Accounting Policies [Line Items]

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No definition available.

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- Definition

Indicates (true false) whether practical expedient is elected to use hindsight in determining lease term and in assessing impairment of right-of-use asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 10
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-Subparagraph (j)
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- Definition

Indicates (true false) whether practical expedients are elected for not reassessing whether any expired or existing contract is or contains lease, lease classification for expired or existing lease, and initial direct cost for any existing lease.

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- Definition

Discount rate used by lessee to determine present value of operating lease payments.

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Reference 1: http://www.xbrl.org/2003/role/exampleRef
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- Definition

Term of lessee's operating lease renewal, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
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- Definition

Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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-Topic 280
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- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

+ References

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- Definition

The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

+ References

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The estimated measure of the maximum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

+ References

No definition available.

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The estimated measure of the minimum percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

+ References

No definition available.

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- Definition

Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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Summary of Significant Accounting Policies - Additional Information (Detail) $ in Thousands			12 Months Ended			59 Months Ended
	Jan. 01, 2020 agreement	Jan. 01, 2018 contract	Dec. 31, 2020 USD ($) Institution item segment	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)	Jun. 30, 2020	Jan. 01, 2019 USD ($) lease	Dec. 31, 2017 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Number of revenue related contracts \| contract		2
Prepaid R&D expense \| $			$ 11,286	$ 8,498
Expected volatility, minimum			71.80%	71.10%	82.60%
Expected volatility, maximum			74.80%	75.20%	92.80%
Expected dividend yield			0.00%	0.00%	0.00%
Cumulative effect adjustment \| $			$ 249,001	$ 186,713	$ 133,630	$ 133,630			$ 86,780
Number of renewable terms			1
Lease, Practical Expedient, Use of Hindsight [true false]			true
Lease, Practical Expedients, Package [true false]			true
Number of operating segments \| segment			1
Number of collaboration and licensing agreements \| agreement	3
Stamford Operating Lease [Member]
Summary Of Significant Accounting Policies [Line Items]
Operating Lease, renewable term			5 years
Annual incremental borrowing rate			7.00%	7.00%
Stamford Operating Lease [Member] \| ASC 842 [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of operating lease \| lease								1
Number of renewable terms			1
Operating Lease, renewable term			5 years
Annual incremental borrowing rate			7.00%
Stamford Operating Lease [Member] \| ASC 842 [Member] \| Cumulative Effect, Period of Adoption, Adjustment [Member]
Summary Of Significant Accounting Policies [Line Items]
Cumulative effect adjustment \| $								$ 0
New Stamford Lease [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of renewable terms			1
Operating Lease, renewable term							5 years
Annual incremental borrowing rate			7.00%
New Stamford Lease [Member] \| ASC 842 [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of renewable terms			1
Operating Lease, renewable term			5 years
Employee Options [Member]
Summary Of Significant Accounting Policies [Line Items]
Expected life of options (in years)			6 years 3 months
Expected volatility, minimum			72.00%	71.00%	83.00%
Expected volatility, maximum			75.00%	75.00%	93.00%
Expected volatility						75.00%
Expected dividend yield			0.00%	0.00%	0.00%
Non Employee Stock Option [Member] \| Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Expected life of options (in years)			10 years
Cash And Cash Equivalents And Marketable Securities [Member]
Summary Of Significant Accounting Policies [Line Items]
Number of financial institutions \| Institution			4